Airplane



Dec. 11, 1928. 1,695,114 1 r c. J. LEISY v 4 AIRPLANE Filed Sept. 29, 1927 INVENTOR O Z/tfrgardefL 6w Patented Dec. 11, 1928.

V UNITED STATES 1,695,114 PATENT OFFICE.

CLIFFORD J'. LEISY, F CLEVELAND, OHIO, ASSIGNOR TO THE GLENN L. MARTIK COM- PANY, OF CLEVELAND, OHIO, A CORPORATIOH OF OHIO.

AIRPLANE.

Application filed September 29, 1827. Serial No. 222,739.

This invention relates to improvements in airplanes, but has to do more part1cularly with pedal controls, as, for instance, a pedal control of the rudder of a plane. Airplanes 5 equipped with a single engine and propeller or with an odd number ofengines and propellers are subject to a tendency to turn or yaw caused by engine torque, that is to say the movement of the propellerblades is downward on one side and upward. on the other and the reaction of the air upon the propeller tends to cause a tilting of the plane about its principal longitudinal axis 1n a direction opposite to the direction of rotation of the propeller. To overcome this tendency and bring the plane to an even keel, thepilot moves the ailerons of the plane. One of 'them is causedto swing down and the other up. The one which is moved downwardly, however, works against air under pressure and, therefore, is more effective than the one which is moved upwardly. The result is the yawing movement mentioned above. This movement must, of course, be overcome if the 2 plane is to fly in a straight course, and it is overcome by the pilot exerting pressure on one of the rudder control pedals. On long flights the constant exertion of this pressure becomes very tiresome.

One of the objects of the present invention therefore is the provision of means which will render unnecessary the constant pressure on one foot pedal, above referred to.

Another object is the provision of resilient means for maintaining a pressure or pull upon a foot pedal, which means may be adjusted to meet the requirements under any given set of conditions.

Another object is the provision of means for instantaneously interrupting the action of said resilient means.

Other objects and features of novelty will appear as I proceed with the description of 45 that embodiment of the invention which, for

the purposes of the present application, I

have illustrated in the accompanying drawing. in which,

Fig. 1 is a perspective view of certain con- 50 trols for an airplane, my invention being applied to one of the control pedals thereof;

F ig. 2 is a detail side elevational view,

partly in section, of this control pedal together with the apparatus for applying ten- 5 sion thereto; and

Fig. 3 is a detail perspective view of a ratchet member employed in connection with to the tube 13.

For the purposes of illustration it is assumed that the engine and propeller rotate in clockwise direction, as viewed from the v rear. The blades of the propeller therefore travel downwardly on the right side and upwardly onthe left. The reaction of the air tends to tilt the plane downwardly toward the left on its longitudinal axis, as heretofore explained. The pilot in order to overcome this tilting tendency turns the wheel 11 to set the ailerons at an angle, that is the left one down and the right one up. Setting the ailerons in this way produces a yawing towards the left on account of the fact that the air encountered by the downwardly turned aileron is compressed and on that account afi'ords more resistance than is afforded to the upwardly turned aileron. Even a difl'erential control of the ailerons does not always entirely eliminate this yawing tendency. To overcome the same the pilot must exert pressure on the right'pedal '15. The present invention provides a substitute for this physical effort which the pilot is otherwise called upon to exert. L

To one of the cranks 16 of the pedal 15 I attach a heavy wire hook 17 with a loop in its free end which holds the looped end of a resilient cord or bungee 18. To some part of the plane frame forward of the pedal I attach, by means of a bracket '19, a pulley '20 over which the resilient cord 18 runs and from which it extends rearwardly to a sition within easy reach of the pilots seat, where it is secured by any suitable means to a winding drum 21. The latter is fixed upon a tubular shaft 22. This shaft is supported in upper and lower bearings in a supporting frame 23, these bearings permitting longitudinal as well as rotary movement.

The upper hearing has an extension on its lower end that is provided with a circular tion of the drum' in one direction.

. upper end of the shaft 22 is supplied with a or knob 28.

, handle 27 by means of which the shaft may be turned to wind up the cord 18 on the drum 21, and with a central hub extension By exerting downward pressure upon the latter or by striking it a light blow the spring 26 may be compressed and the ratchet member 25 carried downwardly out of contact with the ratchet member 24, whereupon the tension in cord 18 rotates the drum 21 and instantaneously relieves the tension in the cord.

When the engine of the airplane is stopped at any time, but particularly just prior to making alanding,'tlie yawing tendency, above described, is removed, and it becomes desirable, if not essential, to relieve the pressure, which previously had been put upon the rudder through the pedal 15 and to do this with as little delay as possible. Otherwise steeringis interfered with at a time when easy and reliable steering is very important. Consequently, the provision which I have made for instantly freeing pedal 15 by means of a light blow is a highly desirable feature of the invention.

Having thus described my invention, I claim: a a

1. In an airplane, a control pedal, a resilient cord attached to said pedal, a winding drum to which the opposite end of said cord is attached, means for turning said drum and forlatching it in adjusted position, and means for releasing said drum instantaneously.

2.-In an airplane, a control edal, a resilient cord attached to said pe al, a drum upon which the opposite end of said cord is wound, means for turning said drum, and ratchet mechanism for holding said drum in adjusted position.

3. In an airplane. a control pedal, a resilient cord attached to said pedal, a drum upon which said cord is wound, means for turning said drum, ratchet mechanism for holding said drum in adjusted position, re-

silient means for holding the parts of, said ratchet mechanism in engagement, and means for overcoming the action of said resilient means.

4. In an airplane, a control pedal, a resilient cord attached to said edal, a winding drum for said cord, a sha for said drum mounted to have slight axial as well-as rotary movement, ratchet mechanism for said drum, resilient means tending to move said shaft axially to hold said mechanism in operative osition, means for turning said shaft, and means for moving it axially against the force of said resilient means.

In testimony whereof, I hereunto afiix my signature.

CLIFFORD J. LEISY. 

